The 2012 film "Last Flight to Abuja" from Nigerian director Obi Emelonye was a disaster thriller based on the true tale of an air crash.

"30 Days in Atlanta," a 2014 film from Nigerian comic Ayo Makun, was the top-earning Nigerian feature ever. It chronicles the adventures of a Nigerian man and his cousin on a monthlong trip to America.

Cinema professors and movie professionals recently met with 30 Nigerian producers at the University of California-Los Angeles film school, where the Nollywood moviemakers heard tips on promoting their burgeoning industry — the world's second largest by number of films produced, trailing India’s Bollywood but ahead of Hollywood.

“It is an industry that employs close to a million people, either directly or indirectly, and has close to about $500 million a year in revenues annually,” said filmmaker Fidelis Duker.

It could have billions in revenue if not for piracy. Pirated DVDs are sold openly in markets, and the Nigerian government has promised to crack down.

Nigeria produces more than 1,000 feature films each year. Most are quickly shot on inexpensive digital equipment. They are typically direct-to-DVD productions, with budgets in the tens of thousands of dollars. Major Hollywood movies can cost $200 million or more.

In two weeks of seminars at UCLA, these producers heard about the art and business of moviemaking. Hollywood actress Diane Ladd, a three-time Oscar nominee, spoke about the importance of collaboration.

“When we in the arts work together, we are promoting culture," Ladd said. "And remember, if this civilization loses its culture, you lose the civilization.”

The 2014 film "Half of a Yellow Sun," starring British actor Chiwetel Ejiofor, was an adaptation of an award-winning African novel, set against the backdrop of the Biafran civil war in Nigeria of the 1960s. Nigerian producers say there are more like these to come.